AT-III is one kind of glycoproteins belonging to .alpha..sub.2 -globurin present in blood plasma and has a molecular weight of 65,000-68,000. It has an inhibitory activity on blood coagulating protease and strongly inhibits coagulative activity of thrombin.
In addition, AT-III has, besides inhibitory activity on thrombin, an inhibitory activity on other coagulation factors such as activated X factor and activated IX factor. It has been reported that AT-III has an inhibitory activity on plasmin and trypsin. These inhibitory activities are known to generally proceed more quickly in the presence of heparin.
AT-III having such pharmacological action is used for the correction of abnormally enhanced coagulation, specifically for the therapy of disseminated intravascular coagulation (DIC).
It has been considered that a reduced placental blood flow is responsible for intrauterine growth retardation (IUGR) observed in gestosis, exerting detrimental effects on fetus. However, a medicament or a method for increasing the decreased placental blood flow has not been found. As a result, the means for protecting the fetus has been the separation of the fetus from the mother, namely, cesarean section.